syzbot


general protection fault in path_init (2)

Status: auto-obsoleted due to no activity on 2023/05/22 23:32
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+d627d3efc95b5fce238c@syzkaller.appspotmail.com
First crash: 422d, last: 422d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in path_init fs 1 956d 944d 0/26 auto-closed as invalid on 2022/01/03 09:55
upstream KMSAN: uninit-value in path_init 7 675d 675d 0/26 closed as invalid on 2022/06/14 13:16

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 28834 Comm: syz-executor.4 Not tainted 6.2.0-syzkaller-02299-g4a7d37e824f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
RIP: 0010:path_init+0xac/0x1930 fs/namei.c:2351
Code: da 48 c1 ea 03 80 3c 02 00 0f 85 89 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 0b 48 89 ca 48 89 4d c8 83 e1 07 48 c1 ea 03 <0f> b6 04 02 38 c8 7f 08 84 c0 0f 85 0a 14 00 00 48 8b 45 c8 31 ff
RSP: 0018:ffffc90004e5f5b8 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: ffff88803561a200 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81e4c93b RDI: ffffc90004e5f868
RBP: ffffc90004e5f650 R08: 0000000000000005 R09: 0000000000200000
R10: 0000000000000040 R11: 0000000000000000 R12: ffffc90004e5f7a0
R13: ffffc90004e5f958 R14: 0000000000000000 R15: ffffc90004e5f7a0
FS:  000055555613c400(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ddbca45088 CR3: 0000000044d6e000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 path_openat+0x182/0x2750 fs/namei.c:3710
 do_filp_open+0x1ba/0x410 fs/namei.c:3742
 file_open_name+0x2ac/0x420 fs/open.c:1257
 filp_open+0x4b/0x80 fs/open.c:1277
 do_coredump+0x10cf/0x3c40 fs/coredump.c:703
 get_signal+0x1bff/0x24e0 kernel/signal.c:2845
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:309
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:568
RIP: 0033:0x7f48720b0e23
Code: ff 7f 0f 84 27 da ff ff 49 8b 84 24 a0 00 00 00 48 85 c0 0f 85 76 02 00 00 89 de 4c 89 e7 44 89 9d 00 fb ff ff 4c 89 8d 08 fb <ff> ff 4c 89 95 10 fb ff ff 48 89 95 20 fb ff ff e8 78 1c 00 00 48
RSP: 002b:00007ffdb3316c80 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 00007f48721abfbf RCX: 00007f48720b0e21
RDX: 00007ffdb3316cc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f48721ad980 R08: 0000000000000000 R09: 00007ffdb33cc080
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000002349de
R13: 00007ffdb3316dd0 R14: 00007f48721ac1f0 R15: 0000000000000fd2
 </TASK>
Modules linked in:
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	48 c1 ea 03          	shr    $0x3,%rdx
   4:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   8:	0f 85 89 15 00 00    	jne    0x1597
   e:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  15:	fc ff df
  18:	48 8b 0b             	mov    (%rbx),%rcx
  1b:	48 89 ca             	mov    %rcx,%rdx
  1e:	48 89 4d c8          	mov    %rcx,-0x38(%rbp)
  22:	83 e1 07             	and    $0x7,%ecx
  25:	48 c1 ea 03          	shr    $0x3,%rdx
* 29:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2d:	38 c8                	cmp    %cl,%al
  2f:	7f 08                	jg     0x39
  31:	84 c0                	test   %al,%al
  33:	0f 85 0a 14 00 00    	jne    0x1443
  39:	48 8b 45 c8          	mov    -0x38(%rbp),%rax
  3d:	31 ff                	xor    %edi,%edi

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/21 23:31 upstream 4a7d37e824f5 42a4d508 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in path_init
* Struck through repros no longer work on HEAD.